Improvement in steam-generators



UNITED STATES PATENT iNIPROVEIViENT `IN STEAM-GENERATORS.

Specification forming part of Letters Patent No. 22,306, dated December 14, 1858.

To all whom t may concern.-

Be it known that I, ROBERT E. ROGERS, of the city and county of Philadelphia, in the State of Pennsylvania, have invented certain new and useful Improvements in Steam-Generators; and I do hereby declare that the following is a full, clear, and exact description of the same, reference being had to the accompanying drawings, which form part of this specification, and to the letters and marks thereon.

My invention has in view the rapid generation of steam of elevated pressure, to effect which I use a compactly-arranged extended heating-surface. I give to such surface full protection from excessive degrees of heat, and I provide for the quick distribution of graduated quantities of water over the extended generating-surface.

To enable others skilled in the art to make and use my invention, I will proceed to describe its construction and operation.

Figure l of the drawings represents my generator, the coils of tubing being shown in a vertical section. Fig. 2 is a top view of the generator, and Fig. 3 a view of one coil with the lower series of the coils embedded in castiron.

a b c d indicate helical coils of tube arranged coneentrically one within another and in such manner that the annular space between each t vo successive coils, and also between the inner coil, a, and the steamchamber e, and between the outer coil, (7., and the surrounding casing or shell f, may be very small and consti tute the only iiues or outlets for the products of combustion. By this arrangement the heated products of combustion and gases are compelled to pass in contact with both sides of each coil, and thereby to more effectually and more economically heat them for the generation of steam. These coils I prefer to use as one coil, or when a large number are employed in groups of several united together as one coil. This I accomplish in the following way: The lower end of the inner coil, a, is connected with the upper extremity of the next coil to it, b, and the lower end of this one connected with the upper extremity of c, and so on for the whole series. The tube g, which I employ as the means of communication between each twov coils, I prefer to make smaller in caliber than that of the coils. The object of having this tube small is to cause any water which may reach the lower lextremity of one coil .to be forcibly carried up to the top of the next coil, which would not be so effectually donewere this connecting-tubeof large caliber.

e indicates th e steam-chamber, placed mostly within the inner coil. lVhen this chamber is dispensed with or placed over the coils instead of in the inner coil, a thick circular plate of iron is supported in its place concentrically within the inner coil, so as to leave a similar annular space for the passage of the heated gases. The object in the construction of this system of coils is to secure the contact of the heated gases with the coils by transmitting those gases through narrow spaces formed between the successive coils.

f indicates the casing of the generator, of sheet-iron or other suitable material, in connection with a proper chimney, 71,.

9,' indicates the fire-box or furnace, and it the grate.

Z marks the cylinder of a steam-engine constructed in the usual way and receiving its supply of steam by the pipe 0 from the steamchamber. A

m marks an airpump, intended to be kept in action by the engine and for forcing atmospheric air into the coil near its upper extremity by the pipe p.

l1 i marks a force-pump for introducing graduated quantities of water into the coil near its upper end by the pipe q. rlhe pipe p is made to enter the coil at a point above where the pipe q enters it. By this arrangement the atmospheric air, which is used for the purpose of accelerating the descent of the water and distributing it along the coil, being forced in above the water accomplishes its end in a very effectual and satisfactory manner.

g indicates one of the pipes which connect the bottom of one coil with the top of the next coil.

fr marks the pipe leading from the last or exterior coil to the steam-chamber.

Fig. 3 represents one of the coils with its portion .s embedded in castiron to protect the tube from being injured by the direct action of the re. The utility of this coating of castiron is evident, since the coils are supported directly over the fire, so that if not adequately protected they are exposed to serious injury. A'esides subserving this end, the cast-iron, by

affording a greater mass of metal, renders the generation of high steam more uniform and less liable to vary by the iiuctuations of the fire.

Supposing the lire to be lighted, the coils sufficiently heated, and the two pumps to have been put in motion, graduated quantities of water are thrown into the upper part of the coil by the water-pu mp, while a supply of compressed atmospheric air is made by means of the air-pump to enter the coil likewise at the upper part and at a point above where the water enters. The water in virtue of its gravity descends along the heated coil, and is thus constantly subjected to fresh evaporating-surfaces, and is thereby converted into steam. This natural descent of the water, which, if left to itself, would be somewhat retarded by the steam generated below it, is greatly accelerated by the atmospheric air which is forced in above it by the air-pump. Thus by these two features of my arrangement-viz., by the introduction of the water and air into the upper part of the coil and by the forcing in of the air at a point above where the water enters-I cause the water to be carried rapidly along the coil and to be spread over the surface of the heated metal and rapidly and regularly converted into steam of a high degree of elasticity.

Another advantage which I gain by introducing the water and air into the upper part of the coil is that the water, by coming rst in contact with the portion of the coil which is less intensely heated than the lower part, is not so liable to be converted into the spheroidal state, which state is well known to be adverse to rapid evaporation.

Having thus fully set outthe construction and operation of my invention, what I claim as new, and desire to secure by Letters Patent, is-

l. The arrangement of the coils constructed as herein described, the one being concentrically within the other, the annular spaces between the successive coils constituting direct and separate and the only passages and outlets for the lproducts of combustion, the entire lower portion of every coil having lire underneath it, and the whole operating as herein set forth.

2. The arrangement of the feedwater pipe and the air-feeding pipe in relation to each other and to the generating-coils, whereby I am enabled to introduce the water in graduated quantities into the upper part of the coil and use atmospheric air to force the water over or upon the heated surfaces, as described.

3. Embedding the lower portion of each of the concentric coils in cast-iron, cast around it to a greater or less height, for the purpose of protecting the coils from high degrees of heat, as herein set forth.

ROBERT E. ROGERS.

\Vit1iesses O. G. HILLIARD, JAs. SAVAGE. 

